1. Field of the Invention
The present invention relates to adhesives suitable for use in elastic composites and disposable absorbent products that are insulted with a solvent comprising an oil. More particularly, the present invention relates to an adhesive that exhibits desired rheological and processing properties so as to provide effective oil-resistant bonds.
2. Description of the Related Art
The use of adhesive materials in disposable absorbent personal care products is generally known. Such adhesive materials are generally employed in absorbent products such as diapers, training pants, adult incontinence products, and feminine care products in order to attach various parts of the product together or to hold a particular part in a desired location.
A disposable absorbent product is generally designed to be insulted during use with various liquids such as water, saline, and body liquids such as urine, menses, and blood. Obviously, it is desired that the disposable absorbent product retains its integrity during use and does not allow leakage of such liquids insulting the product. As such, adhesive materials used in disposable absorbent personal care products are generally not substantially affected by such liquids so as not to substantially lose their adhesive properties during use by a wearer.
However, in addition to such liquids, the disposable absorbent product may also be insulted with oil-based solvents such as baby oil, lotions, ointments, petroleum jellies, sunscreens, or other skin care products. Unfortunately, current adhesive materials used in disposable absorbent products have been found to not be substantially resistant to such oil-based solvents and, as such, substantially lose their adhesive properties during use by a wearer when the disposable absorbent product is insulted with such an oil-based solvent. This typically results in various parts of the disposable absorbent product detaching from each other and/or in an increased incidence of liquid leaks.
For example, a composite comprising elastic threads sandwiched between two substrates may be used within a disposable absorbent product for improved fit and comfort to a wearer or for improved absorbent properties of the disposable absorbent product by reducing the incidence of leaks. An adhesive used to prepare such a composite must generally not only hold the elastic threads in place between the two substrates but also keep the elastic threads from delaminating from the substrates during use. If such an adhesive is not oil-resistant and the elastic composite is insulted with an oil-based solvent, the elastic threads may delaminate from the substrates, possibly resulting in increased liquid leaks as well as reduced fit and comfort to a wearer.
It is therefore desired to develop an adhesive that is generally oil-resistant and yet is easy to process so as to be efficiently used in the preparation of an elastic composite or a disposable absorbent product. Such an elastic composite or a disposable absorbent product would therefore better retain its integrity during use by a wearer when the elastic composite or disposable absorbent product is contacted with an oil-based solvent during such use.